During oil and gas underwater field development, some more and more commonly used subsea equipment include slender structures such as umbilicals, flexibles, and rigid pipes. These slender structures have strong non-linear bending characteristics. Thus, linearized approximations of the bending stiffness of these slender structures are oftentimes not sufficient for ascertaining the bending characteristics of such structures. At the same time, the more complex non-linear bending characteristics cannot be derived directly from theoretical calculations alone. Apparatus and methods have been proposed for conducting bending testing to obtain the accurate bending characteristics of these slender structures.